NORTH RICHLAND HILLS (CBSDFW.COM) - Oak Farms Dairy has renewed their $10,000 reward in the murder case of Marianne Wilkinson, a North Richland Hills woman who was shot at her front door in December 2007. Despite the high profile of the murder case, it has remained unsolved after all these years.

The 67-year-old victim and her husband were at home together when their doorbell rang. Wilkinson answered the door and was then shot by an unknown gunman. There was no known motive for the shooting, and police strongly believe that it may have been a case of mistaken identity — that Wilkinson was not the intended victim.

Despite being nearly six years old, police in North Richland Hills still consider this to be an active case. Authorities said that they are lacking that key piece of evidence needed to close this investigation. However, police added on Monday, there is information leading them toward individuals in the East Texas city of Palestine. The nature of that information was not released, but police think that someone out there may have details that could help detectives wrap up this case.

The $10,000 reward from Oak Farms Dairy is being offered for information that leads to an arrest and indictment in this case. In addition to that reward, Crime Stoppers of Tarrant County is offering another $1,000 for a total of $11,000 in reward money.

Anyone with information on this case is urged to contact the North Richland Hills Police Department at 817-427-7000 or Crime Stoppers at 817-469-8477. Those who offer tips are able to remain anonymous, if desired.